The CZ polycoat doesn't make or allow the pistol to shoot better, but it wears like iron (pardon the pun), and can be touched up with some auto-shop spray paint. It's just another way of protecting the steel under the coating.
I am not sure what it is, but I can tell you that it wears pretty darn well. I have abused mine for years and it still looks darn good. To me it looks as good as the day I got it, but I am sure that it probably isn't quite that good..
I would venture that the coating is a polymer/epoxy mix. I have a couple of Pre-B models that have the same coating, those look almost new with some very slight holster wear. I suspect the pistols were carried a lot and shot just a little.
I noticed that the dan wesson 445 alaskan has what looks like the same finish. This is just a guess from looking at he picture and knowing the two companies merged. I have a cz 75B with the polycoat and am happy with the looks and durabilty.